Voltage regulators typically provide a regulated voltage to a load using a reference voltage. FIG. 1 illustrates a generalized voltage regulator 10 according to the prior art in which an amplifier 12, a feedback circuit 14, and a MOSFET device 16 provide a regulated voltage, Vreg, to a load 18 (represented by a load current IL) using a reference voltage Vref and a supply voltage Vdd. More particularly, amplifier 12 provides a voltage to the gate of MOSFET device 16 in response to the reference voltage and a negative feedback voltage provided by feedback circuit 14. The voltage at the gate of MOSFET device 16 allows a relatively constant current, IL, to flow from MOSFET device 16 to load 18 and generates the regulated voltage at the drain of MOSFET device 16. The regulated voltage feeds into feedback circuit 14 to generate the negative feedback voltage.
Voltage regulator 10 as shown in FIG. 1 may be designed such that the regulated voltage is relatively insensitive to process, temperature, and supply voltage variations. In addition, voltage regulator 10 may employ frequency compensation or stabilization techniques to ensure stability of the feedback system of voltage regulator 10. Many frequency compensation techniques, however, assume a relatively constant load current for voltage regulator 10. If the load current of voltage regulator 10 varies significantly, voltage regulator 10 may become unstable even where frequency compensation techniques are employed.
It would be desirable to be able to provide a voltage regulator that remains stable in response to varying load currents.